1. Field of the Invention
The present invention relates to a portable labeling machine and more particularly to a feed mechanism for use in the portable labeling machine for preventing a continuous label strip from clogging or jamming in the machine.
2. Description of the Prior Art
In one known feed mechanism for a conventional labeling machine, a feed wheel for feeding the continuous label strip includes an open round pocket that is internally ratcheted. There is a first pawl which is engageable with the ratchet teeth of the feed wheel. The first pawl is connected by a protrusion to a member which is made coactive with a trigger, so that the pawl is rocked back and forth by squeezing and releasing of the trigger. The rocking motion of the first pawl intermittently rotates the feed wheel. To prevent reverse rotation of the feed wheel, the trigger has a series of indentations with which a second pawl, having a head portion and a tail portion, is brought into and out of engagement.
It is possible that both the first pawl acting as a feed member of the feed wheel and also the protrusion providing connection with the first pawl may be subjected to an excessive load due either to malfunction of the holding spool of the label strip or to clogging of the label strip. In the case of label clogging, the second pawl for preventing the reverse rotation of the feed wheel should be forcibly released from engagement with the indentations in the course of the squeezing of the trigger so as to remedy the label clogging. While it is in engagement with the indentations, the second pawl is subjected locally at its head edge to such high concentration of stress as to possibly break it.